In Pixar's Cars, retired Piston Cup champion Doc Hudson becomes Radiator Springs' doctor.
Doc Hudson is later revealed to be the famous Hudson Hornet, a racer who won three Piston Cups before a crash ended his career. After racing, he settled in Radiator Springs and served the community as its doctor and sheriff.
His history explains why Doc is skeptical of Lightning McQueen's obsession with publicity and victory. He recognizes both Lightning's talent and the dangers of treating racing as a purely individual pursuit. Doc eventually agrees to help train Lightning for the final Piston Cup race.
The character combines fictional biography with real automotive history: the Hudson Hornet was a genuine American car associated with early NASCAR success. Strip Weathers, known as The King, is another champion in the film, but he does not become Radiator Springs' doctor.